As auxiliary generators become more popular among homeowners due to increased frequency of major storms causing utility power failures, more attention must be paid to safe methods of interfacing to these devices for the uninitiated.
The prior art shows several approaches to this interface problem. In addition, other patents show the use of a key component of this invention in power source switching applications. U.S. Pat. No. 7,471,505 of Gull shows a single load interface box with one manual double-pole transfer switch. A sliding panel on the box front surface only allows the transfer switch to be in the correct position for load-to-generator connection when the male interface plug prongs for the generator connection are exposed.
U.S. Pat. No. 3,808,451 of Pittet uses a combination of a double-pole double-throw (DPDT) power relay and another double-pole power relay to provide a time delay in switching either to or from a generator to control arcing as well as early connection to a generator before its output voltage is in an acceptable range.
U.S. Pat. No. 5,268,850 of Skoglund relates to a computer controlled automatic power-failure and auxiliary generator control where the generator is automatically started and stopped. The power at various loads is monitored by the control computer and a DPDT power relay is used transfer power as appropriate between the utility and generator.
U.S. Pat. No. 7,909,642 of Czarnecki et al. is an outlet center for connecting multiple loads to an auxiliary power source. A simple hole through the wall of a residence connects an outdoor weather protected wall-mounted outlet box with male generator interface plug to a wall-mounted multiple outlet plate on the corresponding interior wall.
As can be seen, a wide variety of interfacing methods of various costs and convenience have been used to connect one or more loads to auxiliary generators. The present invention can be used safely to supply a single selected load from an auxiliary generator by simply plugging the generator into the interface box. In addition, other methods of use permit powering of multiple loads with the present invention.